The former head of world athletics is suspected of receiving just over 1 million euros ($1.09 million) in bribes in 2011 to cover up positive doping tests of Russian athletes, the office of France's financial prosecutor said on Thursday.
Lamine Diack's family dismissed what it called the "excessive and insignificant accusations" and the acting head of the Russian athletics federation said Russia had nothing to fear from the latest scandal to rock world athletics.
Diack, the former head of the International Association of Athletics Federations (IAAF), was placed under formal investigation in France earlier this week on suspicion of corruption and money laundering, prosecutors said.
The accusations revolve around the cover-up of alleged drug cheating by six Russian athletes, the prosecutor's office added, including one who should not have been allowed to participate in the 2012 Olympic Games in London.
"The investigations will have to determine the origins of these sums," a spokesman for the prosecutor's office told Reuters, confirming an earlier media report.
"It's difficult to determine whether the entirety of it comes from the Russian athletics federation, but at least a part of it has gone through this federation."
In a statement issued to Reuters, Diack's family said 16 months of investigation by the IAAF ethics committee led by British lawyer Michael Beloff had not unveiled anything substantial so far.
"The coming days will demonstrate the insignificance of these surreal accusations," the Senegalese man's family added.
Reuters was not immediately able to reach Diack himself for comment.
The spokesman at France's financial prosecutor's office said Diack was released on bail of 500,000 euros and banned from leaving the country.
Russian athletes were at the centre of allegations this year that the IAAF had failed to investigate hundreds of dubious blood tests carried out between 2001 and 2012.
Vadim Zelichenok, the acting head of the Russian athletics federation, told Reuters on Thursday that no one had been in touch with his successors about allegations.
"We have not received one question from any organisation. Therefore, this case does not involve the VFLA in any way at the moment. Let's wait for some official information.
"We do not intend to carry out any individual actions on our own. In my opinion, we are not facing any kind of sanctions."
Zelichenok said new IAAF president Sebastian Coe had met Russian Sports Minister Vitaly Mutko and the president of the Russian Olympic Committee Alexander Zhukov in Moscow in the past few days and had good relationship with the VFLA.
"We are in contact with him a lot. The fact that Coe came to us tells you that he wants to work with us," Zelichenok said.
Earlier this week, Nikita Kamaev of Russia's anti-doping agency RUSADA said in an interview with the Russian R-Sport news agency that his organisation was ready to help French investigators if contacted.
The French investigation followed a complaint by the World Anti-Doping Agency (WADA), which has scheduled a news conference for Monday to address certain findings of its own investigation.
WADA launched a commission to investigate allegations raised during German broadcaster ARD's December 2014 documentary on doping in Russia.
WADA said its goal was "to investigate the validity of allegations of doping practices; corrupt practices around sample collection and results management; and, other ineffective administration of anti-doping processes that implicate Russia, the IAAF, athletes, coaches, trainers, doctors and other members of athletes' entourages; as well as, the accredited laboratory based in Moscow and the Russian Anti-Doping Agency".
The IAAF said it was cooperating with the French investigation.